Is it Confidential? You Can Read Our New Exemption 4 Nutshell for Guidance
Exemption 4 of the FOIA protects trade secrets and commercial or financial information obtained from a person that is privileged or confidential. This exemption is intended to protect the interests of both the government and submitter of information.
The DOI FOIA Policy Office's "Exemption 4 in a Nutshell" breaks down what you need to know about Exemption 4.